4.3.2 The Mammals of Tortola 4.3.2.1 Native Mammals The only native mammals that are still present in the BVI are bats. There are at least six species recorded. Bats often evoke fear and apprehension when discussed or observed by residents. When the IRF field team interviewed local residents about caves and roost for bats, many invariably complained that they had bats in their roofs and asked the team to remove them forthwith. Some refer to these small insectivorous (insect-eating) animals as “rat bats” because of their small dark furry appearance. They are also known as “roof bats.” Contrary to local beliefs and legends, bats are not deaf nor are they blind. They hear extremely wellfar better than humans—and have excellent eyesight, which allows them to see in the night while flying in search of food, avoiding danger, and locating their friends and family. They are excellent fliers, and some species can out-perform most birds in their ability to maneuver their wings in tight spaces, including avoiding objects in pitch-black situations such as caves. They also are not rats, mice or rodents, and none of the species on Tortola drink blood or are vampires! Despite the relative rarity of bats in the Virgin Islands, the species are important, not only because they are native mammals, but also because they play a significant role in the local ecology, e.g., by reducing invertebrate populations, including flies, mosquitoes and moths. Additionally, bats are very useful in helping to spread plant seeds, especially in forests. They also pollinate the flowers of some species of plants such as cacti and the Calabash (C. cujete). They are the primary dispersers of figs (Ficus spp.), which rely on bats to carry their seeds far and wide. Ficus are some of the most important plant species in native forests and ecosystems. Bats were revered by the Amerindians as representatives of their ancestors’ souls. They were often depicted on pottery, carvings and petroglyphs. The closest examples of petroglyph depictions are on St. John in the neighbouring USVI. There is still much to learn and understand about the bats of the Virgin Islands, including the total number
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of species, critical roost sites, and how land development is affecting their habitats. The species of bats for Tortola include a mix of insect, fruit, plant and fish-eating bats. These species are discussed in the following sub-sections. (1) Red Fig-eating Bat (Stenoderma rufum)
Photo 41. The Red Fig-eating Bat of Tortola.
This species is endemic to Puerto Rico and the Virgin Islands, meaning that it is unique to these islands and found nowhere else on earth. There are two subspeciesi.e., a group that has distinctive characteristics and/or behaviour that separates it from other members of the same species. They are S. rufum darioi, found only on Puerto Rico, and S. rufum rufum, found in the Virgin Islands. The Red Figeating Bat prefers intact forest habitat along midto-lower elevations. The IRF team recorded this species for the first time in the BVI on Tortola in February 2014, and only one specimen has been observed so far (Photo 41). It is known only from Brewer’s Bay, an area which is threatened with development and habitat fragmentation. The Red Fig-eating Bat roosts in small colonies in trees and feeds on fruit and possibly leaves. It is sensitive to habitat disturbance, fragmentation, and decline in food and large roosting trees. No roost trees have been observed in Tortola or any of the Virgin Islands thus far.